Tooth vitality after alveolar segmental osteotomy

J. max.-fac. Surg. I (1973) 8:5-91 © Georg Thieme Verlag, Stuttgart

Tooth Vitality after Alveolar Segmental Osteotomy Walter J. Pepersack Department o[ Maxillo-Facial Surgery, Medical Faculty, University of Zurich (Head: Prof. H. L. Obwegeser,M.D., D.M.D.)

Summary Orthodontic surgery of the alveolar process endangers the teeth. The author studied 126 such cases and demonstrates that the percentage of tooth loss is low and that a high number of mobilized teeth no longer demonstrate pain perception, nevertheless retain a normal color and a normal mobility.

Key-Words: Tooth-vitality, orthodontic surgery. Introduction When moving a dentoalveolar segment there is a risk of creating definitive tooth lesions. Wassmund (1935) has expressed his opinion on the subject and draws attention to the animal experiments carried out by Schroeder (1934). The purpose of this study was to determine how frequently root damage, loss of sensitivity and evidence of infection occur following alveolar process surgery. The color and mobility of the teeth were also investigated. The periodontal pocket problem was however not included in this study.

Method A vital tooth is defined as one which has an intact blood supply to its pulp. A vital pulp can be painful so long as its nerve supply is preserved. In the continual practice of alveolar process surgery we need a simple, qui& and precise method of determining a tooth vitality. The problem of pain perception was very well studied by Mumford (1965, 1967). The various newer methods (thermistors, thermography, liquid crystal methods) may well determine the vitality with precision, i.e. the blood supply of the tooth (Howell, Duell and Mullaney 1970) however, these methods are still open to discussion (Brown and Goldberg 1966, Seltzer 1971). The perfectly precise method is still to be found. Most of the available methods never"~Odontotest is manufactured by FRICAR AG, Zurich.

theless are based upon the occurrence of pain, thereby confusing vitality with sensitivity. The former being a function of blood supply and the latter of nerve supply. The author is aware that the method of testing used in this study, i.e. the Odontotest ;:" appliance with CO 2 snow, is subject to the same criticism. However, the precision of the method using the odontotest appliance (Obwegeser and Steinhaeuser 1963) has been demonstrated by Saxer (1958). The non-reacting teeth were all radiographically examined.

Clinical Material In the six year period between June 1965 and June 1971, 429 surgical operations involving movement of the dentoalveolar segments were done in the Department of Maxillofacial Surgery at the University of Zurich: 161 alveolar segmental osteotomies in the mandible, 143 alveolar segmental osteotomies in the maxilla, 125 osteotomies of the maxilla in toto (Type Le Fort I). Among the operations in the maxilla only the segmental alveolar osteotomies (Wassmund 1935, Wunderer 1962) are included in this study. Only those cases which were well examined pre- and postoperatively were included so as to permit a statistically significant study. From the operations performed in the mandible the statistics include 50 cases: 30 eases of various alveolar process surger?', 20 cases with correction of an anterior open bite. The open bite corrections were performed according to the method described by Koele (1959) and involved the insertion of the resected chin fragment between the mobilized alveolar process and the remaining mandibular body.

86

W. ]. Pepersack PERCENT OF MAXILLARY TEETH Wl/H A POSITIVE POSTOPERATIVE

RETURN OF SENSmVffY AND INCIDENCE OF

REACTION % too

TOOTH DAMAGE FOLLOWING MAXILLARY PROCEDURES

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1,ENDANGERED 2.pOSTOPERATWELY:

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267 65,7 97,1 01 O

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557 94,5 2 (0,3~) 29 (5 %) 1 0

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Results All teeth in the mobilized fragment were considered endangered as well as those teeth adjacent to the line of vertical osteotomy in the non-mobilized part of the jaw. In the diagrams appearing below, the following symbols are used to indicate the various possibilities: Mx : Maxilla. Md : Mandible. M : Tooth situated in the mobilized fragment. N : Tooth situated in tile non-mobilized part of the maxilla (MxN) or mandible (MdN).

S

TOTAL Mx

NUMBER OF TEETH

19 - Positbelj reactlrcJ -Positively mactFn9 in % 1oo -Damaged teeth 0 -Non r~ctin9 t~th o Endodontic treatment 0 o -Extracted

MxMS

A

MxMS

t

5O

3o

MxMAI

: Tooth adjacent to a vertical osteotomy, either with simultaneous extraction: AE, or without extraction: AO. : Tooth adjacent to a supplementary osteotomy in the mobilized fragment.

All teeth can then be divided into six categories, in the maxilla as well as in the mandible as follows: : Tooth in the maxilla (Mx), in the MxM mobilized fragment (M), not in the vicinity of any osteotomy. MxMS : Tooth in the maxilla (Mx), in the mobilized fragment (M), adjacent to a supplementary osteotomy (S). MxMAE : Tooth in the maxilla (Mx), in the mobilized fragment (M), adjacent to

Osteotamy with extmcttan

Fig. 2 a vertical osteotomy with extraction (AE). MxMAO : Tooth in the maxilla (Mx), in the mobilized fragment (M), adjacent to a vertical osteotomy without extraction (AO). MxNAE : Tooth inthe maxilla (Mx), in the nonmobilized part (N), adjacent to a vertical osteotomy with extraction (AE). MxNAO : Tooth in the maxilla (Mx), in the non mobilized part (N), adjacent to a vertical osteotomy without extraction (AO). When in the mandible, the symbol (Md) will be used instead of (Mx), for common cases, and the categories will be preceded by the letter K if the procedure was a Koele one (e.g. KMdMAO). 1. Return of sensitivity after maxillary procedure (fig. 1) a) In most cases a positive response appears between the third and sixth postoperative months. Approximately 400/o of all the teeth react positively at the end of the third month and 850/0 at the end of the sixth month. b) Between the sixth and twelfth postoperative months a positive response is obtained in an additional 10% of the involved teeth. At the end of the twelfth postoperative month 94.5°/0 of all endangered teeth react positively.

Tooth Vitality after Alveolar Segmental Osteotomy PERCENTAGE OF MANDIBULAR TEETH WITH A POSITIVE POSTOPERATIVE REACTION

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RETURN OF SENSITIVITy A N D INCIDENCE OE TOOTH DAMAGE FOLLOWING MANDIBULAR PROCEDURES

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NUMBER OF TEETH 1.ENDANGERED 2. POSTOPERATIVELY:

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87

- Positivelyreac~ing -P~iti~ly re~tlng in% *Damaged teeth -Non mactlng teeth

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TOTAL Mfl 245 177 72,3 4 (1,5%) 64 (25 %) 3

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c) After the twelfth postoperative month very few of the non-reacting teeth will revert to a positive reaction later. d) As could be expected, the non-mobilized teeth adjacent to the vertical osteotomy respond positively early following the operation in a high percentage of cases.

a) As in the maxilla, a positive reaction appears in most cases between the third and sixth postoperative months. However, the number of positively reacting teeth at the end of the first year is only 72.50/0.

2. The status of the various groups of teeth in the maxilla at the end of the twelfth month (Fig. 2) a) The apices of 2 of the 588 endangered teeth were damaged (0.3%). Both of these damaged teeth were found in cases in which extractions had been done simultaneously with the osteotomy, one in the mobilized fragment and one in the non-mobilized fragment. One of the teeth was treated endodontically. b) 29 teeth (ca. 5%) gave no reaction to CO 2 snow. A m o n g these, only 5 were in the nonmobilized part, all the others were in the mobilized fragment. None of the teeth required endodontic treatment. c) The largest number (14°/0) of the non-reacting teeth was found in the group M x M A O which were in the mobilized fragment and adjacent to the vertical osteotomy when no extraction was done.

3. Return of sensitivity in the mandibular teeth excluding the Koele operation (Fig. 3) Recovery of sensitivity is somewhat different than in the maxilla.

b) After the twelfth postoperative month very few on the non-reacting teeth will react with a positive response.

4. The status of the various groups of teeth in the mandible at the end of the twelfth month (Koele operation excluded) (Fig. 4) a) The apices of 4 o f the endangered teeth were damaged, i.e. ca. 1.50/0 or five times more frequently than in the maxilla. Of these 4 teeth, 2 were in the non-mobilized part and were adjacent to the osteotomy when no extraction was done. b) 64 teeth, i.e. ca. 25°/0 (also five times more frequently than in the maxilla) failed to respond to stimulation. c) 3 of the 4 damaged teeth were treated endodontically. d) No tooth was extracted. e) It is noteworthy that the apical lesions occurred in the mandible when no tooth was extracted prior to the osteotomy. f) In those cases in which a supplementary vertical osteotomy of the mobilized fragment was done in order to achieve a more desirable arch

88

W. ]. Pepersack RETURN OF SENSITIVITYAND INCIDENCE OF TOOTH DAMAGE FOLLOWING KOLE OPERATIONS

\ NUM

F:ig. form, a very high percentage (53.5%) of the teeth adjacent to the supplementary osteotomy of the mobilized fragment showed an anesthesia. Next in order of frequency are those teeth which are simply adjacent to the primary line of osteotomy and in the mobilized fragment (44.20/0). 5. No attempt has been made to present an analytical diagram of the mandibular teeth following the Koele operation since there were only 20 such cases in this study. However, the situation at the end of the first postoperative year can be estimated (Fig. 5). a) 12 of the 178 endangered teeth sustained some damage (6.50/@ This is to be compared to 1.5% of damaged teeth in the other procedures of mandibular alveolar surgery. b) The 12 teeth involved were situated as follows: 5 in the non-mobilized part and adjacent to the osteotomy. 3 in the mobilized fragment and adjacent to the osteotomy. 4 adjacent to a supplementary osteotomy of the mobilized fragment. c) 72 of the 178 teeth (40°/0) gave no response to CO2 snow. d) 5 of the damaged teeth were extracted. e) 2 damaged teeth were endodontically treated. Discussion The opinion of Hovell (1971) that "what matters in segmental surgery is that the involved teeth do

not discolor or become gangrenous and that the pulp remains vascular" summarizes the common clinical point of view regarding surgery of the alveolar process. Everyday experience confirms this fact, it seemed nevertheless interesting to study more accurately the dental damage brought about by segmental osteotomy. Publications on the subject were, until recent years, very sparse. The task of compiling such an analysis is not an easy one. It involves precise operative documentation (clinical examination, vitality, mobility tests, X-rays) and regular postoperative examinations executed with the same accuracy. Last but not least the amount of available patients has to be large if one desires meaningful statistics. Due to the large number of patients operated upon in the Maxillofacial Surgery Department at the University of Zurich, Switzerland, we have been able to maintain precise control of 126 files representing 41% of 304 cases involving alveolar segmental surgery of the jaws between 1965 and 1971. This number of operations does not include 125 Le Fort I maxillary osteotomies, as previously mentioned. Despite the fact that we were able to compile a large amount of material it appeared impossible to compare various methods such as the Wassmund (1935) and the Wunderer (1962) in the maxilla or to take into account the number of millimeters the mobilized fragment was moved and in which direction. This is due to the fact that the corrections were so numerous (upward, upward and backward, forward, forward and upward, rotation etc), their importance so variable, the bone cuts so individual, that we abandoned attempts to group them into various types of corrections. Moreover, we are not convinced of the importance of these details. For the same various reasons it was impossible to study the sequence of return of a positive reaction in every single tooth of the mobilized fragment. The study of the influence of age was not significant since all our patients were of the younger age group. Sex differences were not found. The prominent result of our investigation was the confirmation that the actual rate of tooth loss is very small. However, the maxilla and the mandible give different percentages of tooth lesions and of non-reactive teeth, these both being far more frequent in the mandible. The higher rate of damage in the mandibular teeth can be explained

Tooth Vitality after Alveolar Segmental Osteotmny by the greater difficulty of the surgical approach. This is also illustrated by the fact that the damages due to the vertical osteotomy in the m a n d i b l e are greatly reduced when a tooth has been extracted before the osteotomy. T h e supplementary split of the mobilized fragment has the d i s a d v a n t a g e also, in the mandible, of a higher percentage of loss of vitality in the central incisors. T h e fact that m a n y more teeth remain non-reactive in the mandible might be p a r t i a l l y due to the different vascular and nervous supply in the m a n dible, also to the bony structure and the location of the bone cut. This could also explain the very high occurrence of lesions in the Koele (1959) procedure. W h e n the surgeon tries to keep as much bone as possible between the apical cut and the mobilized chin, this m a y endanger the apices. In considering the work of Madritsch (1968), his findings coincide most often with ours: non-reacting teeth are more frequent in the m a n d i b l e (300/0) than in the m a x i l l a (6.50/0) and far more frequent a d j a c e n t to the vertical osteotomy than in the r e m a i n d e r of the mobilized fragment. H e also noticed that the root lesions were almost always (13 out of 15) due to the vertical osteotomy and that when they occurred in other teeth they were due to the abnormal length of these teeth. The lesions were ahnost always discovered during the operation and very clear on the X - r a y .

89

T h e interest in dental lesions associated with segmental alveolar surgery has increased in recent years as can be seen in the literature. Johnson and Hinds (1969), Leibold et al. (1971) confirm that despite the fact that in m a n y teeth it is impossible to evoke a painful sensation after surgery, the greatest number of them retain a normal color, a normal mobility and a normal X - r a y appearance. A d d i t i o n a l research is needed in order to improve our knowledge on this subject. T h e work of Bell (1969) on the monkey shows the m a n y vascular anastomoses which preserve the osseous and the p u l p a r vascularity in segmental surgery. This author was able to demonstrate that "if the horizontal osteotomy was made 0.5 cm or more from the apices of the teeth there was no interruption of p u l p a l circulation". Ware and Ashamalla (1971) showed in the monkey that no p u l p a l modification occurred after forward movement of the u p p e r teeth when the labial mucosal attachments were preserved. Poswillo (1972) also in animal experiments on monkeys was able to prove that after segmental surgery a progressive fibrosis occurs in the pulp of the mobilized teeth with total loss of odontoblasts. No nerve fibers remained, but the teeth remained viable and the vaseularity was retained. Hutchinson and MacGregor (1972) express the opinion, after a clinical survey in man, that a viable dental pulp persists after segmental

Table I Summary of tooth damage risks involved in orthodontic surgery of the alveolar processes.

Number of patients Number of patients requiring subsequent extraction of a tooth Per cent of patients requiring subsequent extraction of a tooth Number of endangered teeth Number of extracted teeth Per cent of extracted teeth Number of patients requiring endodontic treatment Per cent of patients requiring endodontic treatment Number of teeth requiring endodontic treatment Per cent of teeth requiring endodontic treatment

Maxillary procedures

Mandibular procedures (K61e operations excluded)

K6Ie procedures

76 0 0 588 0 0

30 0 0 245 0 0

20 2 10 178 5 3

1 1.3 1 0.2

3 10 3 1.2

2 10 2 1.1

Number of patients with non-reactive teeth requiring no treatment Per cent of patients with non-reactive teeth requiring no treatment

21 30

20 65

15 75

Per cent of patients without loss of tooth or endodontic treatment

98.7

90

S0

90

W.J. Pepersack: Tooth Vitality after Alveolar Segmental Osteotomy

osteotomies, the blood supply having been maintained. The vessels may transmit proprioceptive impulses along their perivascular nerves. They refer to histological evidence of the presence of nerve fibers in a vascular pulp after autotransplants and MacGregor (1970) reports a case of segmental osteotomy in which a tooth was accidentally lost 6 months after the operation; this tooth was histologically examined and showed nerve fibers. In our clinical material we occasionally observed that a tooth damaged at the level of the apex, showed after many months no sign of infection and had pain sensation with CO s snow. Hutchinson and MacGregor (1972) among 7 damaged teeth (3 apically) had only one tooth which did not respond to all of their tests. W e believe that only histologic investigations can explain these facts, as well as others. For example, that after a Koele (1959) operation on the mandible in which a portion of the chin is inserted in the gap between the elevated alveolar process and the intact part of the mandible, sensation of the teeth returns in a reasonably favorable percentage of cases. The last diagram will summarize the practical point of view of this type of surgery and enable us to have an idea of the tooth damage risk involved in orthodontic surgery of the alveolar processes (Table 1).

Conclusions As can be concluded from table 1, the number of teeth requiring either endodontic treatment or

References Bell, W.: Revascularization and bone healing after anterior maxillary osteotomy: A study using adult rhesus monkeys. J. oral Surg. 27 (1969) 249 Brown, A., M. Goldberg: Surface temperature and temperature gradients of human teeth in situ. Arch. oral Biol. 11 (1966) 973 HovelI, J.: In: MacGregor, A.: Histology of a pulp following segmental alveolotomy. Brit. J. oral Surg. 8 (1971-1972) 292 Howell, R., R. Duell, R. Mullaney: The determination of pulp vitality by thermographic means using cholesterie liquid crystals. Oral Surg. 29 (1970) 763 Hutchinson, D., A, MacGregor: Tooth survival following various methods of sub-apical osteotomy. Int. J. oral Surg. 1 (1972) 81 Johnson, ]., E. Hinds: Evaluation of teeth vitality after subapical osteotomy. J. oral Surg. 27 (t969) 256 KoeIG H.: Nouvelles interventions chirurgicales ~t la hauteur du proeessus alveolaire en rue de la correc-

extraction is low. Both the number of patients with residual non-reacting teeth and the percentage of non-reacting teeth per se, could be impressive. One must, however, remember that all non-reactive teeth which did not require extraction or endodontic treatment, retained a normal color and mobility and showed no sign of putpal death. This tends to indicate that a normal vascular supply is maintained. Experience and precision play a great role. The percentage of apical lesions and of non-reacting teeth is higher in the hands of less experienced surgeons. To estimate with accuracy the risk of tooth damage, precise pre- and postoperative examination nmst be done (tooth vitality, clinical examination, X-rays). These are easily forgotten and we then believe that it is not possible to have meaningful statistics. Postoperatively these examinations should be done every two months for one year. It would be interesting to conduct a two year survey. The recent literature shows the greater interest of the authors for the problem and research will certainly go forward with clinical surgery to further enhance our understanding of the total problem.

Acknowledgement The author expresses his gratitude to Lt. Col. D. Shelton of the U.S. Army, Dental Corps for his assistance in correcting the english version of this publication.

tion des malformations de l'arcade et des malpositions dentaires. Rev. belge Stomat. 56 (1959) 247 Leibold, D., H. TiIson, K. Rash: A subjective evaluation of the reestablishment of the neurovascular supply of teeth involved in anterior maxillary osteotomy procedures. Oral Surg. 32 (1971) 531 MacGregor, A.: Histology of a pulp following segmental alveolotomy. Brit. J. oral Surg. 8 (1970-1971) 292 Madritsch, E.: Spfitergebnisse nach Korrektur yon Dysgnathien und Zahnstellungsanomalien dutch Alveolarfortsatzbewegungen und Kortikotomien. Diss, Univ. Zfirich 1968 Mumford, J.: Pain perception threshold and adaptation of normal human teeth. Arch. oral Biol. 10 (1965) 957 Mumfor& J.: Pain perception threshold on stimulating human teeth and the histological condition of the pulp, Brit. dent. J. 123 (1967) 427

N. S&wenzer: Correction of Noses Associated with Clefts of Lip and Palate

91

Obwegeser, H. L., E. Steinhaeuser: Ein neues Ger/it

Ware, W., M. Ashamalla: Pulpal response following

zur Vitalit~tsprfifung der Z/ihne mit Kohlens/iureschnee. Schweiz. Mschr. Zahlheilk. 73 (1963) 1001 Poswillo, D.: Early pulp changes following reduction of open bite by segmental surgery. Int. J. oral Surg. 1 (1972) 87 Saxer, A.: Die Vitalit/itsprtifung der Z/ihne. Diss., Univ. Zfirich 1958 Schroeder, H.: Die MSglichkeiten orthodontischer Osteotomien und ihr Einflut~ anf das Leben der Pulpa. Dtsch. zahn/irztl. Wschr. 40/41 (1934) 946 Seltzer, S.: Advances in biology of the human dental pulp. Oral Surg. 32 (1971) 454

anterior maxillary osteotomy. Oral Surg. 60 (1971) 156 Wassmund, M.: Lehrbuch der praktischen Chirurgie des Mundes und der Kiefer, Bd. I. Meuser, Leipzig 1935 Wunderer, S.: Die Prognathie-Operation mittels frontal gestieltem Maxillafragment. Ust. Z. Stomat. 59 (1962) 98 Walter ]. Pepersack, M.D., D.M.D., Kieferchirurgische Abteilung, Plattenslrasse 11, Postfach, CH-8028 Zilri&, Switzerland

J. max.-fac. Surg. 1 (1973) 91-95 © Georg Thleme Verlag, Stuttgart

Correction of Noses Associated with Clefts of Lip and Palate Norbert Schwenzer Department of Oral and Maxillo-Facial Surgery of the Institute of Dental Medicine, University of Tubingen, W. Germany (Head: Prof. N. Schwenzer, M.D., D.M.D.)

Summary A supplementary correction of the nose in clefts of lip and palate cannot always be avoided, even where primary repair in infancy was optimal. The degree of existent deformity is, by far, dependent on the severity of the cleft and on the traumatisation during the primary surgical intervention. Since only in mild deformities do the usual procedures in the corrective nasal plastic operation yield satisfactory results, but however, not in severe cases, the author prefers uncovering the nasal framework using the Decortication Technique. The necessary nasal correction is, as a rule, achieved together with the often essential correction or reoperation of the lip. If convenient, the anterior portion of the cleft alveolus is simultaneously corrected. In extreme cases, autologous or homologous preserved cartilage is additionally used to build the cartilaginous nasal framework. Examples have been included to illustrate the technique.

Key-Words: Secondary rhinoplasty, cleft lip and palate. Introduction In modern surgery of cleft lip a n d palate, the actual closure of cleft should be accorded the same significance as the establishment of normal form and function of nose. Although through the improvement on the methods of p r i m a r y repair -

which also includes p r i m a r y osteoplasty -- favourable conditions for later development of the nose can be created, corrective surgery is, in most adult cases, unavoidable. This fact is explicable when one examines the morphology of the nose in cleft lip, which has been fully described by Huffman and Lierle (1949), Trauner and Wirth (1957), Lindsay and Farhas (1972). The following characteristics are peculiar to noses of cleft lips: 1. Flattened ala on the cleft side. Its lateral crus is displaced caudo-dorsally and is atrophied. T h e medial crus is, in unilateral clefts, distorted to the healthy side. 2. Deviation of lamina quadrangularis to the healthy side. 3. Dorsal and lateral displacement of m a x i l l a r y portion of the cleft side which forms the bony base of the nose. The above-mentioned anomalies could be more or less pronounced. The degree of severity is directly dependent on: a) the form of cleft, that is, severe nasal deforrnities are expected more frequently in complete clefts than in isolated clefts of lip,